Charging circuit and charger
The charging circuit with adaptive voltage processing and detection mechanisms addresses high production costs by using lower-specification components to handle grid voltage fluctuations, ensuring normal operation and cost reduction.
Patent Information
- Application Number
- CN202411362241.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-27
- Publication Date
- 2024-12-31
AI Technical Summary
Chargers face significant production cost increases due to the need for high-voltage resistance components to accommodate wide fluctuations in AC power grid voltages, which can damage internal circuits.
A charging circuit with a first and second filtering circuit, a voltage processing module, a switch tube, and a control module that detects and adjusts the working mode of the voltage processing module based on detected voltages to maintain normal operation using lower withstand voltage components.
The solution allows chargers to adapt to wide fluctuations in grid voltage while reducing production costs by using lower-specification power components and preventing voltage-related damage.
Smart Images
Figure CN119231701A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the field of charging technology, and specifically relates to a charging circuit and a charger. Background Art
[0002] A charger is a voltage converter that outputs direct current that meets charging requirements after a series of processes such as rectification, filtering, and voltage transformation of the alternating current input from the AC power grid.
[0003] At present, the voltage of AC power grids around the world varies greatly, which may cause the input voltage of chargers to fluctuate widely in different places, which may cause the internal circuit of the charger to be damaged, such as burned, when used in some places. In order to solve this problem, the relevant technology is to select power devices with higher voltage resistance specifications in the charger, such as power switch modules and rectifier filter output modules, to adapt to the wide range of input voltage fluctuations.
[0004] However, using power devices with higher voltage specifications in chargers may lead to a significant increase in the production cost of the charger. Therefore, how to reduce the production cost of the charger while ensuring that the charger can adapt to the large fluctuations of the AC power grid in different places is an urgent problem to be solved. Summary of the invention
[0005] The purpose of the embodiments of the present application is to provide a charging circuit and a charger, which can reduce the production cost of the charger while being compatible with a wide range of fluctuations in grid voltage.
[0006] In a first aspect, an embodiment of the present application provides a charging circuit, which includes: a first filtering circuit, a second filtering circuit, a voltage processing module, a first switch tube, a first detection circuit and a control module; the first end of the first filtering circuit is connected to the first end of the voltage processing module, the first end of the second filtering circuit is connected to the first end of the first switch tube, the second end of the first switch tube is connected to the first end of the voltage processing module, the third end of the first switch tube is connected to the first end of the control module, the second end of the voltage processing module is connected to the second end of the control module, the first end of the first detection circuit is connected to the first end of the second filtering circuit, and the second end of the first detection circuit is connected to the third end of the control module; wherein the first detection circuit is used to detect a first voltage on the second filtering circuit; the control module is used to control the working mode of the voltage processing module according to the enabling state of the first switch tube and the first voltage, and the working mode includes any one of the following: pass-through mode, boost mode, and buck mode.
[0007] In a second aspect, an embodiment of the present application provides a charger, which includes the charging circuit as described in the first aspect.
[0008] In the embodiment of the present application, since the magnitude of the voltage on the filter circuit can reflect the grid voltage and the voltage that the charging element located after the filter circuit in the charging circuit needs to withstand; therefore, by detecting the voltage on the second filter circuit and controlling the working mode of the voltage processing module according to the detected voltage and the enabling state of the first switch tube in series on the second filter circuit, it is possible to avoid the voltage being too high or too low after being processed by the voltage processing module, thereby ensuring that the charger can maintain normal operation when the grid voltage is high or low on the basis of using power elements with lower withstand voltage specifications in the charger. In this way, the charger can adapt to the wide range of fluctuations in the grid voltage and reduce the production cost of the charger. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Figure 1 It is a structural schematic diagram of a charging circuit in the related art;
[0010] Figure 2 It is one of the structural schematic diagrams of the charging circuit provided in the embodiment of the present application;
[0011] Figure 3 This is the second structural schematic diagram of the charging circuit provided in the embodiment of the present application;
[0012] Figure 4 This is the third structural diagram of the charging circuit provided in the embodiment of the present application;
[0013] Figure 5 This is the fourth structural diagram of the charging circuit provided in the embodiment of the present application;
[0014] Figure 6 This is the fifth structural diagram of the charging circuit provided in the embodiment of the present application;
[0015] Figure 7 This is the sixth structural diagram of the charging circuit provided in the embodiment of the present application;
[0016] Figure 8 This is the seventh structural diagram of the charging circuit provided in the embodiment of the present application;
[0017] in, Figures 2 to 7 The reference numerals in the figures are respectively:
[0018] 10-charging circuit; 20-first filtering circuit; 30-second filtering circuit; 40-voltage processing module; 41-boost module; 42-buck module; 43-pass-through module; 50-first switch tube; 60-first detection circuit; 70-control module; 80-second detection circuit; 90-AC grid input module; 100-rectifier module; 110-isolation transformer; 120-rectifier filter output module; 130-second switch tube. DETAILED DESCRIPTION
[0019] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.
[0020] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.
[0021] The charging circuit provided in the embodiment of the present application is described in detail below through specific embodiments and application scenarios in conjunction with the accompanying drawings.
[0022] The charger is a voltage converter that converts the input high-voltage AC power from the AC grid into safe low-voltage DC power after internal rectification and filtering, isolation transformer and output rectification and filtering. Its internal circuit design is complex and belongs to the circuit architecture of multi-module application.
[0023] Figure 1 A schematic diagram of a conventional charger circuit is shown in FIG. Figure 1 As shown, the AC grid input voltage enters the rectifier module 302 through the AC grid input module 301 for rectification, which is called DC power. Then the DC power passes through a series of filter capacitor modules 303 to form a high-voltage DC power supply. The control module 305 controls the power switch module 304 to be turned on, so that the high-voltage DC power supply is transferred from the primary of the isolation transformer module 306 to the secondary of the isolation transformer module 306, and finally passes through the rectifier filter output module 307 to generate a stable low-voltage DC power output to power the terminal device.
[0024] However, the voltage of AC power grids around the world varies greatly, such as from tens of volts to hundreds of volts, which may cause the input voltage of the charger to fluctuate widely in different places, which may cause the internal circuit of the charger to be damaged, such as burned, when used in some places. In order to solve this problem, the relevant technology is to select power devices with higher voltage resistance specifications in the charger, such as power switch modules and rectifier filter output modules, to adapt to the wide range of input voltage fluctuations.
[0025] However, using power devices with higher voltage specifications in chargers may lead to a significant increase in the production cost of the charger. Therefore, how to reduce the production cost of the charger while ensuring that the charger can adapt to the large fluctuations of the AC power grid in different places is an urgent problem to be solved.
[0026] In order to solve the above technical problems, an embodiment of the present application provides a charging circuit, which includes: a first filtering circuit, a second filtering circuit, a voltage processing module, a first switch tube, a first detection circuit and a control module; the first end of the first filtering circuit is connected to the first end of the voltage processing module, the first end of the second filtering circuit is connected to the first end of the first switch tube, the second end of the first switch tube is connected to the first end of the voltage processing module, the third end of the first switch tube is connected to the first end of the control module, the second end of the voltage processing module is connected to the second end of the control module, the first end of the first detection circuit is connected to the first end of the second filtering circuit, and the second end of the first detection circuit is connected to the third end of the control module; wherein the first detection circuit is used to detect the first voltage on the second filtering circuit; the control module is used to control the working mode of the voltage processing module according to the enabling state of the first switch tube and the first voltage; wherein the working mode includes any one of the following: pass-through mode, boost mode, and buck mode. Through this solution, since the magnitude of the voltage on the filter circuit can reflect the grid voltage and the voltage that the charging element of the charging circuit located after the filter circuit needs to withstand; therefore, by detecting the voltage on the second filter circuit and controlling the working mode of the voltage processing module according to the detected voltage and the enabling state of the first switch tube in series on the second filter circuit, it is possible to avoid the voltage being too high or too low after being processed by the voltage processing module, thereby ensuring that the charger can maintain normal operation when the grid voltage is high or low on the basis of using power components with lower withstand voltage specifications in the charger. In this way, the charger can adapt to the wide range of fluctuations in the grid voltage and reduce the production cost of the charger.
[0027] The present application embodiment provides a charging circuit, such as Figure 2 As shown, the charging circuit 10 may include: a first filter circuit 20, a second filter circuit 30, a voltage processing module 40, a first switch tube 50, a first detection circuit 60 and a control module 70. The first end of the first filter circuit 20 is connected to the first end of the voltage processing module 40, the first end of the second filter circuit 30 is connected to the first end of the first switch tube 50, the second end of the first switch tube 50 is connected to the first end of the voltage processing module 40, the third end of the first switch tube 50 is connected to the first end of the control module 70, the second end of the voltage processing module 40 is connected to the second end of the control module 70, the first end of the first detection circuit 60 is connected to the first end of the second filter circuit 30, and the second end of the first detection circuit 60 is connected to the third end of the control module 70.
[0028] Among them, the first detection circuit 60 can be used to detect the first voltage on the second filter circuit 30; the control module 70 can be used to control the working mode of the voltage processing module 40 according to the enable state of the first switch tube 50 and the first voltage, and the working mode can include any one of the following: pass-through mode, boost mode, and buck mode.
[0029] It should be noted that the working modes of the voltage processing modules are different, and the voltage processing modes process the voltage in different ways.
[0030] Specifically, when the voltage processing module is in the pass-through mode, the voltage processing module is equivalent to a conductor, which is responsible for transmitting the voltage output by the filter circuit to the isolation transformer behind the voltage processing module;
[0031] When the voltage processing module is in boost mode, the voltage processing module is responsible for increasing the voltage output by the filter circuit and transmitting it to the isolation transformer;
[0032] When the voltage processing module is in the step-down mode, the voltage processing module is responsible for reducing the voltage output by the filter circuit and transmitting it to the isolation transformer. In this way, since the voltage processing module can first increase, reduce or directly transmit the charging voltage, the charging circuit can still maintain normal operation even if the voltage of the external power supply connected to the charging circuit fluctuates widely.
[0033] In some embodiments of the present application, the enabling state of the first switch tube includes: disconnection and conduction.
[0034] In some embodiments of the present application, the first switch tube is used to control the conduction and disconnection of the second filter circuit. Among them, when the first switch tube is turned on, the second filter circuit is turned on, so that the first filter circuit and the second filter circuit both participate in filtering; when the first switch tube is turned off, the second filter circuit is turned off, so that the first filter circuit participates in filtering, and the second filter circuit does not participate in filtering. It can be understood that the control module grid input voltage controls the enabling operation of the second filter circuit, so that it works at a low voltage input, so that on the basis of reducing the withstand voltage and volume of the power components in the second filter circuit, the capacity effect equivalent to that of the traditional capacitor can be achieved, thereby reducing the volume and cost of the filter capacitor.
[0035] In some embodiments of the present application, the first switch tube may be any possible switch such as a switch transistor or a field effect tube.
[0036] In some embodiments of the present application, the withstand voltage level of the power element in the second filter circuit is lower than the withstand voltage level of the power element in the first filter circuit. In this way, the production cost of the charging circuit can be reduced.
[0037] In some embodiments of the present application, the control module may be specifically used for:
[0038] When the first switch tube is turned on and the first voltage is greater than or equal to the first voltage threshold, the voltage processing module is controlled to be in a pass-through mode; or,
[0039] When the first switch tube is turned on and the first voltage is greater than or equal to the second voltage threshold and less than the first voltage threshold, the voltage processing module is controlled to be in a boost mode; or,
[0040] When the first switch tube is disconnected and the first voltage is less than the second voltage threshold, the voltage processing module is controlled to be in a voltage reduction mode.
[0041] In some embodiments of the present application, the first voltage threshold is greater than the second voltage threshold.
[0042] In the embodiment of the present application, “the first switch tube is turned on, and the first voltage is greater than or equal to the first voltage threshold” means that the voltage of the direct current after being processed by the filter circuit is within the withstand voltage range of the power device after the filter circuit, so there is no need for the voltage processing module to perform additional processing on the voltage;
[0043] “The first switch tube is turned on, and the first voltage is greater than or equal to the second voltage threshold and less than the first voltage threshold” means: the voltage of the DC power processed by the filter circuit is small, that is, the grid voltage is in an undervoltage input state, which may trigger the low voltage protection mechanism of the charging circuit. Therefore, the voltage processing module can increase the voltage to ensure the normal operation of the charging circuit;
[0044] “The first switch tube is disconnected, and the first voltage is less than the second voltage threshold” means: the voltage of the DC power processed by the filtering circuit is relatively large, which may trigger the over-voltage protection mechanism of the charging circuit or may cause damage to the power devices in the charging circuit. It also means that the grid voltage is in a high voltage or over-voltage input state; therefore, the voltage processing module can reduce the voltage to ensure the normal operation of the charging circuit.
[0045] In this way, through the enable state of the first switch tube and the relationship between the first voltage and the first voltage threshold and the second voltage threshold, it is possible to accurately determine whether the voltage of the direct current entering the voltage processing module is too large or too small, thereby controlling the working mode of the voltage processing module according to the enable state of the first switch tube and the relationship between the first voltage and the first voltage threshold and the second voltage threshold. The charging voltage can be controlled more accurately to avoid damage to the power components in the charging circuit, thereby improving the reliability of the charging circuit.
[0046] In some embodiments of the present application, Figure 2 ,like Figure 3As shown, the voltage processing module 40 may include: a boost module 41, a buck module 42 and a pass-through module 43. The first end of the boost module 41, the first end of the buck module 42 and the first end of the pass-through module 43 are all connected to the first end of the first filter circuit 20 and the second end of the first switch tube 50; the second end of the boost module 41, the second end of the buck module 42 and the second end of the pass-through module 43 are all connected to the second end of the control module 70.
[0047] The control module 70 may be specifically used for:
[0048] By controlling the pass-through module 43 to work, the voltage processing module 40 is controlled to be in the pass-through mode; or,
[0049] By controlling the boost module 41 to work, the voltage processing module 40 is controlled to be in boost mode; or,
[0050] By controlling the voltage reduction module 42 to operate, the voltage processing module 40 is controlled to be in the voltage reduction mode.
[0051] In some embodiments of the present application, the control module is specifically configured to perform any of the following:
[0052] 1. When the first switch tube is turned on and the first voltage is greater than or equal to the first voltage threshold, the voltage processing module is controlled to be in the pass-through mode by controlling the pass-through module to work;
[0053] 2. When the first switch tube is turned on and the first voltage is greater than or equal to the second voltage threshold and less than the first voltage threshold, the voltage processing module is controlled to be in the boost mode by controlling the boost module to work;
[0054] 3. When the first switch tube is disconnected and the first voltage is less than the second voltage threshold, the voltage processing module is controlled to be in the voltage reduction mode by controlling the voltage reduction module to operate.
[0055] In some embodiments of the present application, the control module may control the operation of the boost module, the buck module and the pass-through module by sending control signals to the boost module, the buck module and the pass-through module.
[0056] In some embodiments of the present application, the boost module may be any one of the following: a high-frequency oscillation circuit, a pulse transformer, or a pulse transformer.
[0057] In some embodiments of the present application, the buck module may be any one of the following: a series regulator tube voltage regulator circuit, a three-terminal integrated voltage regulator circuit, and a buck converter.
[0058] In this way, since the voltage processing module includes a boost module, a buck module and a pass-through module connected in parallel, the control module can control the boost module, the buck module or the pass-through module to work to control the voltage processing module to work in different modes, which can avoid the voltage after being processed by the voltage processing module being too high or too low, so that the charger can maintain normal operation when the grid voltage is high or low on the basis of using power components with lower withstand voltage specifications in the charger. In this way, the charger can adapt to the wide range of fluctuations in grid voltage and reduce the production cost of the charger.
[0059] In some embodiments of the present application, Figure 3 ,like Figure 4 As shown, the first detection circuit 60 may include a first resistor R1 and a second resistor R2. The first end of the first resistor R1 is connected to the first end of the second filter circuit 30, the second end of the first resistor R1 and the third end of the control module 70 are both connected to the first end of the second resistor R2, and the second end of the second resistor R2 is grounded. The first voltage is the divided voltage on the second resistor R2.
[0060] In some embodiments of the present application, Figure 4 The control module 40 can collect the divided voltage V on the second filter circuit 30 through the first resistor R1 and the second resistor R2. R2 , that is, the voltage on the second resistor R2.
[0061] Among them, V R2 =V C2 *R2 / (R1+R2), V C2 is the voltage on the second filter circuit.
[0062] In some embodiments of the present application, the first resistor and the second resistor may also be referred to as voltage-dividing resistors.
[0063] It should be noted that the first voltage threshold and the second voltage threshold are much smaller than the output voltage or the operating voltage of the external power supply.
[0064] In this way, the voltage on the second resistor is positively correlated with the voltage on the second filter circuit. Therefore, by collecting the voltage on the second resistor, the voltage on the second filter circuit can be accurately monitored, and then combined with the voltage division on the second resistor to control the working mode of the voltage processing module, the working mode of the voltage processing module can be made more matched with the input voltage of the voltage processing module, thereby ensuring that the power components behind the filter circuit are not damaged and ensuring that the charger can maintain normal operation when the grid voltage is high or low.
[0065] In the charging circuit provided by the present application, since the magnitude of the voltage on the filter circuit can reflect the grid voltage and the voltage that the charging element located after the filter circuit in the charging circuit needs to withstand; therefore, by detecting the voltage on the second filter circuit and controlling the working mode of the voltage processing module according to the detected voltage and the enabling state of the first switch tube connected in series on the second filter circuit, it is possible to avoid the voltage being too high or too low after being processed by the voltage processing module, thereby ensuring that the charger can maintain normal operation when the grid voltage is high or low on the basis of using power elements with lower withstand voltage specifications in the charger. In this way, the charger can adapt to the wide range of fluctuations in the grid voltage and reduce the production cost of the charger.
[0066] In some embodiments of the present application, Figure 2 ,like Figure 5 As shown, the charging circuit 10 provided in the embodiment of the present application may further include: a second detection circuit 80; a first end of the second detection circuit 80 is connected to an external power supply, and a second end of the second detection circuit 80 is connected to a fourth end of the control module 70.
[0067] The second detection circuit 80 can be used to detect the second voltage of the external power supply. The control module 70 can also be used to:
[0068] When the second voltage is less than the third voltage threshold, the first switch tube 50 is controlled to be turned on; or,
[0069] When the second voltage is greater than or equal to the third voltage threshold, the first switch tube 50 is controlled to be turned off.
[0070] In some embodiments of the present application, the external power supply may be an AC power grid power supply.
[0071] In some embodiments of the present application, the second voltage is much greater than the first voltage, and the second voltage is an AC grid voltage.
[0072] In some embodiments of the present application, the second voltage is less than the third voltage threshold, indicating that the voltage of the external power supply is low, such as the charging circuit is in a low grid voltage input or grid undervoltage input state. The second voltage is greater than or equal to the third voltage threshold, indicating that the voltage of the external power supply is high, such as the charging circuit is in a grid overvoltage input state.
[0073] It can be understood that the control module can control the second filter capacitor to work when the input voltage of the charging circuit is low based on the voltage detected by the second detection circuit, so as to work in parallel with the first filter circuit to provide sufficient capacitance for the charging circuit; and control the second filter circuit to disconnect when the input voltage of the charging circuit is high, thereby avoiding damage to the power devices in the second filter circuit.
[0074] It can be understood that the control module can control the first switch tube to be turned on when the input voltage of the charging circuit is low, and control the first switch tube to be turned off when the input voltage of the charging circuit is high. That is, by controlling the enabling state of the first switch tube, the second filter circuit can only participate in filtering when the input voltage is low to provide sufficient specific capacitance; and does not participate in filtering when the input voltage of the charging circuit is high. Therefore, even if the withstand voltage level of the power element in the second filter circuit is low, the charging circuit can still maintain normal operation when the grid voltage fluctuates in a large range.
[0075] It should be noted that, in the above embodiment, the control module compares the second voltage with the third voltage threshold as an example. In actual implementation, a more detailed voltage threshold can be set for more precise control; it can be achieved that when the charging circuit is in a low voltage or undervoltage input, the second filter circuit is controlled to work, and when the charging circuit is in a high voltage or overvoltage input state, the second filter circuit is controlled not to work.
[0076] Exemplarily, a fourth voltage threshold, a fifth voltage threshold and a sixth voltage threshold may be set. The fourth voltage threshold is less than the fifth voltage threshold, and the fifth voltage threshold is less than the sixth voltage threshold. Thus, the control module may be used to:
[0077] When the second voltage is less than the fourth voltage threshold, it is determined that the charging circuit is in a grid undervoltage input state, so that the first switch tube can be controlled to be turned on, so that the first filter circuit participates in filtering; or,
[0078] When the second voltage is greater than or equal to the fourth voltage threshold and less than the fifth voltage threshold, it is determined that the charging circuit is in a low-voltage grid input state, so that the first switch tube can be controlled to be turned on or remain turned on, so that the first filter circuit participates in filtering; or
[0079] When the second voltage is greater than the fifth voltage threshold, it is determined that the charging circuit is in a grid high voltage input state, so that the first switch tube can be controlled to be disconnected to avoid damage to the power element in the second filter circuit; or
[0080] When the second voltage is greater than the sixth voltage threshold, it is determined that the charging circuit is in a grid overvoltage input state, so that the first switch tube can be controlled to be disconnected or remain disconnected to avoid damage to the power elements in the second filter circuit.
[0081] In this way, since the control module can control the first switch tube to disconnect according to the voltage detected by the second detection circuit to control the second filter circuit not to work when the input voltage is high, conventional voltage-resistant devices can be used in the second filter circuit to replace high-specification voltage-resistant devices to achieve the same circuit function, thereby reducing the production cost of the charger.
[0082] In some embodiments of the present application, Figure 5 ,like Figure 6 As shown, the second detection circuit 80 may include a first diode D1 and a third resistor R3; the anode of the first diode D1 is connected to the external power supply, the cathode of the first diode D1 is connected to the first end of the third resistor R3, and the second end of the third resistor R3 is connected to the fourth end of the control module 70.
[0083] In some embodiments of the present application, the second voltage V2=V R3 *I R3 , where V R3 is the resistance value of the third resistor, I R3 is the current value passing through the third resistor.
[0084] It can be understood that the diode has unidirectional conductivity. Specifically, the resistance of the diode is very small under the action of forward voltage, which is equivalent to the switch of the path being opened; the resistance is very large under the action of reverse voltage, which is equivalent to the switch of the circuit being closed, thereby playing the role of a switch.
[0085] It should be noted that the above embodiment is illustrated by taking the example that the second detection circuit includes a diode and a resistor. In actual implementation, the second detection circuit may also be any other possible detection circuit.
[0086] In this way, the second voltage, that is, the input voltage of the charging circuit, that is, the grid voltage, can be detected by the first diode and the third resistor connected in series. Therefore, the input voltage of the charging circuit can be accurately detected on the basis of reducing the number of components in the charging circuit, thereby ensuring that the control module can accurately control the enabling state of the first switch tube based on the voltage detected by the second detection circuit.
[0087] In some embodiments of the present application, Figure 5 ,like Figure 7 As shown, the charging circuit 10 may further include: an AC power grid input module 90 and a rectifier module 100. The first end of the AC power grid input module 90 is connected to an external power source, the second end of the AC power grid input module 90 is connected to both the first end of the rectifier module 100 and the first end of the second detection circuit 80, and the second end of the rectifier module 100 is connected to both the second end of the first filter circuit 20 and the second end of the second filter circuit (30); wherein the AC power grid input module 90 may be used to input AC power from an external power source;
[0088] The rectifier module 100 can be used to convert alternating current into direct current.
[0089] It can be understood that the rectifier module 100 can input the converted DC power into the first filter circuit, or into the first filter circuit and the second filter circuit, which needs to be determined according to the enabling state of the first switch tube.
[0090] Specifically, if the first switch tube is turned on, the rectifier module can input the converted DC power into the first filter circuit and the second filter circuit respectively. Otherwise, the rectifier module can input the converted DC power into the first filter circuit respectively, and the second filter circuit is disconnected.
[0091] It can be understood that the first filter circuit and the second filter circuit are used to filter the direct current converted by the rectifier module.
[0092] It should be noted that see Figure 7 The second detection circuit 80 is connected to the external power supply through the AC power grid input module 90.
[0093] Specifically, the first end of the second detection circuit 80 is connected to the second end of the AC power grid input module 90. Figure 7 ,like Figure 8 As shown, the anode of the first diode D1 in the second detection circuit 80 is connected to the second end of the AC power grid input module 90 to achieve connection with an external power source through the AC power grid input module 90 .
[0094] In some embodiments of the present application, the AC grid input module may be a plug.
[0095] In some embodiments of the present application, the rectifier module may include any one of the following: a bridge distillation circuit, a full-wave rectifier circuit, a multi-phase rectifier circuit, and a single-phase rectifier circuit.
[0096] In some embodiments of the present application, Figure 8 As shown, the first filter circuit 20 may include a first filter capacitor C1, and the second filter circuit 30 may include a second filter capacitor C2;
[0097] The first end of the first filter capacitor C1 is connected to the second end of the rectifier module 100 and the first end of the voltage processing module 40, and the second end of the first filter capacitor C1 is grounded;
[0098] A first end of the second filter capacitor C2 is connected to a first end of the first switch tube 50, and a second end of the second filter capacitor C2 is grounded;
[0099] The second end of the first switch tube (50) is also connected to the second end of the rectifier module (100).
[0100] It should be noted that, when the first filter circuit and the second filter circuit respectively include a filter capacitor, the first end of the filter circuit and the second end of the filter circuit have a common end, and both are the first ends of the corresponding filter capacitors.
[0101] Specifically, the first end of the first filter circuit and the second end of the first filter circuit are both the first end of the first filter capacitor, and the third end of the first filter circuit is the second end of the first filter capacitor;
[0102] The first end of the second filter circuit and the second end of the second filter circuit are both the first end of the second filter capacitor, and the third end of the second filter circuit is the second end of the second filter capacitor.
[0103] In some embodiments of the present application, the voltage resistance level of the first filter capacitor is greater than the voltage resistance level of the second filter capacitor.
[0104] For example, the withstand voltage of the aluminum foil of the first filter capacitor may be 600V, and the withstand voltage of the aluminum foil of the second filter capacitor may be 250V.
[0105] For another example, the withstand voltage of the aluminum foil of the first filter capacitor may be 650V, and the withstand voltage of the aluminum foil of the second filter capacitor may be 260V.
[0106] For another example, the withstand voltage of the aluminum foil of the first filter capacitor may be 550V, and the withstand voltage of the aluminum foil of the second filter capacitor may be 230V.
[0107] It should be noted that the capacitance formula of a capacitor can be: C = (K*S) / d, where K is the dielectric constant between the two electrodes inside the capacitor, S is the effective area between the two electrodes inside the capacitor, and d is the thickness between the two electrodes of the capacitor, that is, the thickness of the withstand voltage insulating medium of the capacitor. When the withstand voltage of the aluminum foil material of the capacitor is low, the thickness of the electrode of the capacitor will also decrease. Since the withstand voltage of the aluminum foil material of the capacitor is negatively correlated with the specific capacitance of the capacitor (unit: uF / cm2), that is, the lower the withstand voltage of the aluminum foil of the capacitor, the higher the capacitance ratio of the capacitor, and the higher the capacitance ratio of the capacitor, the higher the effective area between the two electrodes inside the capacitor, therefore, when the capacitance of the capacitor remains unchanged, the lower the withstand voltage of the aluminum foil material used in the capacitor, the smaller the volume of the capacitor, thereby reducing the size of the charging circuit and the charger having the charging circuit. Alternatively, when the volume of the capacitor remains unchanged, the lower the withstand voltage of the aluminum foil material used in the capacitor, the higher the capacitance of the capacitor.
[0108] In this way, using a capacitor in the filter circuit can simplify the structure of the filter circuit and reduce the size of the charging circuit and the charger while ensuring the normal operation of the charging circuit.
[0109] In some embodiments of the present application, Figure 7As shown, the charging circuit 10 provided in the embodiment of the present application may further include: an isolation transformer 110 and a rectifier filter output module 120 .
[0110] The first end of the isolation transformer 110 is connected to the third end of the voltage processing module 40, the second end of the isolation transformer 110 is connected to the first end of the rectification and filtering output module 120, and the second end of the rectification and filtering output module 120 is connected to the charging device;
[0111] The isolation transformer 110 can be used to reduce the voltage of the DC power output by the voltage processing module 40;
[0112] The rectification and filtering output module 120 can be used to rectify and filter the direct current output by the isolation transformer 110 .
[0113] In some embodiments of the present application, the rectification and filtering output module may include an output rectification power device and a plurality of output filtering capacitors. For the specific structure, please refer to the relevant technology.
[0114] In some embodiments of the present application, Figure 7 As shown, the charging circuit 10 may further include: a second switch tube 130, a first end of the second switch tube 130 is connected to the third end of the isolation transformer 110, a second end of the second switch tube 130 is grounded, and a third end of the second switch tube 130 is connected to the fifth end of the control module 70;
[0115] The control module 70 may also be used to control the working state of the charging circuit by controlling the enabling state of the second switch tube 130 .
[0116] In some embodiments of the present application, the enabling state of the second switch tube may include: on and off. The control module may control the second switch tube to be on to control the charging circuit to work; or the control module may control the second switch tube to be off to control the charging circuit to stop working.
[0117] Combine the following Figure 8 The charging circuit 10, the circuit working principle and the working process provided in the embodiment of the present application are described in detail.
[0118] It should be noted that Figure 8 This is a specific circuit diagram of the charging circuit 10 provided in this application.
[0119] like Figure 8 As shown, a first end of the AC grid input module 90 is connected to an external power source, a second end of the AC grid input module 90 is connected to the positive electrode of the first diode D1 and the first input end of the rectifier module 100 respectively, and a third end of the AC grid input module 90 is connected to the second input end of the rectifier module 100;
[0120] The cathode of the first diode D1 is connected to the first end of the third resistor R3, and the second end of the third resistor R3 is connected to the first pin of the control module 70;
[0121] The first output end of the rectifier module 100 is connected to the first end of the first filter capacitor C1 and the second end of the first switch tube 50 respectively, and the second output end of the rectifier module 100 is grounded;
[0122] The first end of the first switch tube 50 is connected to the first end of the second filter capacitor C2, the second end of the first switch tube 50 is also connected to the first end of the boost module 41, the first end of the buck module 42 and the first end of the pass-through module 43 respectively, and the third end of the first switch tube 50 is connected to the second pin of the control module 70; the second end of the first filter capacitor C1 and the second end of the second filter capacitor C2 are both grounded;
[0123] The second end of the boost module 41, the second end of the buck module 42 and the second end of the pass-through module 43 are all connected to the third pin of the control module 70, and the third end of the boost module 41, the third end of the buck module 42 and the third end of the pass-through module 43 are all connected to the first end of the isolation transformer 110;
[0124] The second end of the isolation transformer 110 is connected to the first end of the rectifier filter output module 120, the third end of the isolation transformer 110 is connected to the first end of the second switch tube 130, the second end of the second switch tube 130 is grounded, and the third end of the second switch tube 130 is connected to the fourth pin of the control module 70;
[0125] The first end of the first resistor R1 is connected to the first end of the second filter capacitor C2, the second end of the first resistor R1 is connected to the first end of the second resistor R2 and the 5th pin of the control module 70 respectively, the second end of the second resistor R2 is grounded, and the 6th pin of the control module 70 is grounded.
[0126] It can be seen that the first end of the control module is the second pin of the control module, the second end of the control module is the third pin of the control module, the third end of the control module is the fifth pin of the control module, the fourth end of the control module is the first pin of the control module, the fifth end of the control module is the fourth pin of the control module, and the sixth pin of the control module is grounded.
[0127] It is understandable that Figure 8 As shown, the pass-through module 43 may include a second diode D2 , wherein an anode of the second diode D2 is connected to the second end of the first switch tube 50 and the first output end of the rectifier module 100 , respectively.
[0128] Figure 8 The working principle of the charging circuit 10 shown may include:
[0129] The first pin of the control module 70 samples and detects the voltage Vin on the AC power grid input module 90 through the first diode D1 and the resistor R2, which is the second voltage. Multiple voltage thresholds are set inside the control module 70, such as V1, V2, V3, V4, where V4 is the third voltage threshold. And it is set that when the condition a1: V1 < Vin < V2 is satisfied, it is a low power grid voltage input; when the condition a2: V2 < Vin < V3 is satisfied, it is a high power grid voltage input; when the condition a3: Vin < V1 is satisfied, it is a power grid undervoltage input; when the condition a4: Vin > V3 is satisfied, it is a power grid overvoltage input.
[0130] (1) When V1 < Vin < V2, it is a low power grid voltage input. After the control module 70 detects that Vin satisfies this condition a1 through the first pin, it controls the second pin to output a control signal b1 to control the first switching transistor 5050 to conduct, so that the second filter capacitor C2 is connected to the circuit and works.
[0131] The first filter capacitor C1 and the second filter capacitor C2 work in parallel, greatly increasing the total capacitance of the filter capacitor. Since the second filter capacitor C2 is connected and works when the power grid voltage input is low, its withstand voltage can be greatly reduced compared to the first filter capacitor C1, and a higher capacitance can be achieved in a lower-cost or smaller-volume way, meeting the total capacitance requirements of the charging circuit 10 for the first filter capacitor C1 and the second filter capacitor C2 under low voltage and large current.
[0132] After the first switching transistor 50 conducts, the voltage dividing resistors R1 and R2 can collect the voltage dividing signal V on the second filter capacitor C2 R2 , and it can be known that V R2 = V C2 * R2 / (R1 + R2). If the control module 70 detects through the fifth pin that the voltage signal V on the R2 resistor R2 is less than the third voltage threshold V4, it can output a control signal c1 through the third pin to control the voltage processing module 40 to be in a direct-through working state through the second diode D2.
[0133] (2) When Vin < V1, it is a power grid undervoltage input, and the traditional charging circuit 10 architecture will protect the charger from working anymore. And Figure 8 In the charging circuit 10 shown, the control module 70 detects the power grid input voltage through the first pin, that is, the second voltage satisfies the condition a2, so it outputs a control signal b2 through the second pin to control the first switching transistor 50 to conduct, so that the second filter capacitor C2 and the first filter capacitor C1 work in parallel together; in (2), the first switching transistor 50 has already conducted, and the control module 70 detects the voltage V on the R2 resistor through the fifth pin R2Condition a3 is satisfied, thus determining that the power grid is in an undervoltage state. The control module 70 can output a control signal c2 through the third pin to control the voltage processing module 40 to perform boost operation through the boost module 41. In this state, after being filtered by the first filter capacitor C1 and the second filter capacitor C2, the first high-voltage DC power supply Va undergoes boost control by the boost module 41 to generate a second-stage high-voltage DC power supply Vb-1, meeting the minimum high-voltage DC voltage requirement during the operation of the charger. Furthermore, the charger can switch from the traditional undervoltage protection state to the normal operation state.
[0134] (3) When the second voltage satisfies condition a2, that is, V2 < Vin < V3, it is a high power grid voltage input. When the second voltage satisfies condition a4, that is, Vin > V3, it is a power grid overvoltage input. After the control module 70 detects through the first pin that the second voltage satisfies condition a3 or condition a4, it can output a control signal b3 through the second pin to control the first switch 50 to turn off, so as to control the second filter capacitor C2 to disconnect from the circuit, that is, the second filter capacitor C2 does not participate in filtering.
[0135] In (3), the first switch 50 has been turned off. At this time, the voltage at the first end of the second filter capacitor C2 is at a low level. When the control module 70 detects through the fifth pin that the voltage V R2 across the second resistor R2 is at a low level, it is determined that the power grid voltage is in a high voltage or overvoltage input state. Thus, the control module 70 can output a control signal c3 through the third pin to control the voltage processing module 40 to perform buck operation through the buck module 42. Thus, after the first high-voltage DC power supply Va filtered by the first filter capacitor C1 undergoes buck control by the buck module 42 to generate a third-stage high-voltage DC power supply Vb-2, it operates normally. The converted third-stage high-voltage DC power supply Vb-2 is lower than the voltage of the voltage processing module 40, reducing the withstand voltage requirement for the second switch 130. The withstand voltage of the second switch 130 can be reduced from the existing 800V specification to 600V or even lower; after the third-stage high-voltage DC power supply Vb-2 passes through the isolation transformer 110, it is rectified and filtered by the rectifier filter output module 120. It can be understood that since the voltage of the third-stage high-voltage DC power supply Vb-2 has been bucked down, the voltage of the rectifying power device in the rectifier filter output module 120 also further decreases, so that the withstand voltage of the power components in the rectifier filter output module 120 can be reduced from the 150V specification to 100V or even lower.
[0136] It should be noted that in the related art, when the grid input voltage meets condition 2 or 4, the traditional charging circuit will enter the overvoltage protection state or the internal circuit components will be damaged when there is no overvoltage protection. In the present application, the voltage reduction control of the voltage reduction module in the voltage processing module is used to make the voltage processed by the voltage processing module produce a voltage drop, such as lower than V2, so that there is no need to trigger the overvoltage protection and ensure that the power components are not damaged.
[0137] It should be noted that the ratio of the input voltage to the output voltage of the isolation transformer is proportional to the turns ratio of the transformer coil.
[0138] In the charging circuit provided by the embodiment of the present application, on the one hand, the control module controls the enabling operation of the second filter circuit according to the grid input voltage, so that it works when the voltage input is low, so that the capacity effect equivalent to that of the traditional capacitor can be achieved on the basis of reducing the withstand voltage and volume of the power element in the second filter circuit, so that the volume and cost of the filter capacitor can be reduced. On the other hand, the control module detects the voltage division on the second filter capacitor through the first resistor and the second resistor, and then controls the voltage processing module to convert the filtered voltage into a new DC power supply for the next stage, which can reduce the withstand voltage specification requirements of the primary power switch device, such as the second switch tube 130 and the secondary rectifier filter output module, and uses conventional withstand voltage devices to replace high-specification withstand voltage devices to achieve the same circuit function, saving design costs. In this way, according to the combined application of the enabling working state of the second filter capacitor and the voltage processing module, the charging circuit can work stably and normally when the input is overvoltage or undervoltage, expanding the input grid voltage range and grid compatibility of the charger.
[0139] It should be noted that the above embodiment is illustrated by taking the application of the filtering function (i.e., the first switch tube and the second filtering capacitor) and the voltage processing module in the charging circuit as an example. In actual implementation, either the voltage processing module or the filtering function can be applied. In other words, the filtering function and the voltage processing module can be independently designed to work in the charging circuit without conflict.
[0140] Among them, when the second filter capacitor and the first switch tube are independently used in the charging circuit, the charger can reduce the capacity requirements of the filter capacitor when high-voltage grid input or low-voltage grid input, and reduce the capacitor withstand voltage requirements, design cost and volume.
[0141] When the voltage processing module is independently used in the charging circuit, the voltage withstand specification requirements of the rectifier power devices of the second switch tube and the rectifier filter output module can be reduced according to the internal power conversion function of the voltage processing module, while reducing the production cost and design cost of the rectifier power devices of the second switch tube and the rectifier filter output module.
[0142] In some embodiments of the present application, the second filter capacitor and the first switch tube may be separate devices or may be packaged into one module.
[0143] In some embodiments of the present application, the control logic of the control module has multiple implementation methods, for example, it can be implemented by analog circuit control or software burning control.
[0144] It should be noted that the above embodiment uses AC to DC conversion as an example to illustrate the charging circuit. In actual implementation, the charging circuit of the present application can also be a DC to DC circuit architecture.
[0145] The present application also provides a charger, which may include the charging circuit in the above embodiment. The charger can implement each process of the above charging circuit embodiment and achieve the same technical effect.
[0146] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.
[0147] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, a disk, or an optical disk), and includes a number of instructions for a terminal (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present application.
[0148] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.
Claims
1. A charging circuit, characterized in that: The charging circuit includes: a first filter circuit, a second filter circuit, a voltage processing module, a first switch tube, a first detection circuit and a control module; The first end of the first filter circuit is connected to the first end of the voltage processing module, the first end of the second filter circuit is connected to the first end of the first switch tube, the second end of the first switch tube is connected to the first end of the voltage processing module, the third end of the first switch tube is connected to the first end of the control module, the second end of the voltage processing module is connected to the second end of the control module, the first end of the first detection circuit is connected to the first end of the second filter circuit, and the second end of the first detection circuit is connected to the third end of the control module; Wherein, the first detection circuit is used to detect the first voltage on the second filtering circuit; The control module is used to control the working mode of the voltage processing module according to the enabling state of the first switch tube and the first voltage, and the working mode includes any one of the following: a pass-through mode, a boost mode, and a buck mode.
2. The charging circuit according to claim 1, characterized in that: The control module is specifically used for: When the first switch tube is turned on and the first voltage is greater than or equal to a first voltage threshold, controlling the voltage processing module to be in a pass-through mode; or, When the first switch tube is turned on and the first voltage is greater than or equal to a second voltage threshold and less than the first voltage threshold, controlling the voltage processing module to be in a boost mode; or, When the first switch tube is disconnected and the first voltage is less than the second voltage threshold, the voltage processing module is controlled to be in a step-down mode.
3. The charging circuit according to claim 2, characterized in that: The voltage processing module includes: a boost module, a buck module and a pass-through module; The first end of the boost module, the first end of the buck module, and the first end of the pass-through module are all connected to the first end of the first filter circuit and the second end of the first switch tube; The second end of the boost module, the second end of the buck module and the second end of the pass-through module are all connected to the second end of the control module; Wherein, the control module is specifically used for: By controlling the pass-through module to work, the voltage processing module is controlled to be in the pass-through mode; or, By controlling the boost module to work, the voltage processing module is controlled to be in boost mode; or, By controlling the step-down module to work, the voltage processing module is controlled to be in step-down mode.
4. The charging circuit according to any one of claims 1 to 3, characterized in that: The first detection circuit includes a first resistor and a second resistor; The first end of the first resistor is connected to the first end of the second filter circuit, the second end of the first resistor and the third end of the control module are both connected to the first end of the second resistor, and the second end of the second resistor is grounded; The first voltage is the divided voltage on the second resistor.
5. The charging circuit according to claim 1 or 2, characterized in that: The charging circuit further includes: a second detection circuit; The first end of the second detection circuit is connected to an external power supply, and the second end of the second detection circuit is connected to a fourth end of the control module; Wherein, the second detection circuit is used to detect the second voltage of the external power supply; The control module is also used for: When the second voltage is less than a third voltage threshold, the first switch tube is controlled to be turned on; or, When the second voltage is greater than or equal to the third voltage threshold, the first switch tube is controlled to be turned off.
6. The charging circuit according to claim 5, characterized in that: The second detection circuit includes a first diode and a third resistor; The anode of the first diode is connected to the external power supply, the cathode of the first diode is connected to the first end of the third resistor, and the second end of the third resistor is connected to the fourth end of the control module.
7. The charging circuit according to claim 5, further comprising: AC grid input module and rectifier module; The first end of the AC power grid input module is connected to the external power supply, and the second end of the AC power grid input module is connected to the first end of the rectifier module and the first end of the second detection circuit. The second end of the rectifier module is connected to the second end of the first filter circuit and the second end of the second filter circuit; Wherein, the AC power grid input module is used to input the AC power of the external power supply; The rectifier module is used to convert the alternating current into direct current.
8. The charging circuit according to claim 7, characterized in that: The first filter circuit includes a first filter capacitor, and the second filter circuit includes a second filter capacitor; The first end of the first filter capacitor is connected to the second end of the rectifier module and the first end of the voltage processing module, and the second end of the first filter capacitor is grounded; The first end of the second filter capacitor is connected to the first end of the first switch tube, and the second end of the second filter capacitor is grounded; Wherein, the second end of the first switch tube is also connected to the second end of the rectifier module.
9. The charging circuit according to claim 1 or 8, characterized in that: The withstand voltage level of the power element in the second filter circuit is lower than the withstand voltage level of the power element in the first filter circuit.
10. The charging circuit according to claim 7, characterized in that: The charging circuit also includes: an isolation transformer and a rectifier filter output module; The first end of the isolation transformer is connected to the third end of the voltage processing module, the second end of the isolation transformer is connected to the first end of the rectification and filtering output module, and the second end of the rectification and filtering output module is connected to the charging device; Wherein, the isolation transformer is used to step down the direct current output by the voltage processing module; The rectification and filtering output module is used to rectify and filter the direct current output by the isolation transformer.
11. The charging circuit according to claim 10, characterized in that: The charging circuit further includes: a second switch tube, wherein a first end of the second switch tube is connected to a third end of the isolation transformer, a second end of the second switch tube is grounded, and a third end of the second switch tube is connected to a fifth end of the control module; Wherein, the control module is further used to control the working state of the charging circuit by controlling the enabling state of the second switch tube.
12. A charger, characterized in that: The charging circuit comprises the charging circuit as claimed in any one of claims 1 to 11.